Melting-hearth for electric induction-furnaces.



0. GRUNWALD. MEI-TING HEARTH FOR ELEGTRIG'INDUGTION FURNACES.

., APPLICATION I FILED MAY 7, 1909. I 1943 ,403, Patented Dec. 14, 1909. 1:

U I E STATES PATENT onr cu.

CARL .GRUNWALiD, or; BREDENEY, GERMANY.

MELTINGPHEARTH ron ELECTRIC. rnnuctrromrumvncns;

To all whomit may concernffi Be it known that I CAnnGnUNwALn, a subject of the German Emperor. and resi dent of 3S Essenerstrasse', Bredeney, near Essen (Ruhr), Germany, have invented oertai l new and useful Improvements in Melting-Hearths for .Electric Induction-Furn'aces, of which the following is a specification. I

The present invention relates to the. particular formation of the melting hearth of electric induction furnaces. I

Formerly the melting trough of suchfurnac'es was generally made circular and pen at the top. The materialtobe treate was in such case introduced from. above into the trough which was-provided with aremovable cover. This arrangement has great disadvantages in as farjas-it'makes'it ext'rernely diftieult to servethe: melting hearth and causes great losses in upward radiation when the furnace is being served. Furthermore it is very difficult 'to charge suchfur- .nace's mechanically. his true that in some other electric induction furnaces the meltin I trough is closed at the'top and isprovid with lateralserving openings. However in these furnaces thesha'pe of the melting trough and theearrangement ,of the serving openings are selected in such a manner that only a part of themelting trough is accessible through the serving openings. In accordance with the present invention these drawbacks are removed by forming the melting trough in such a manner andbyproviding it with lateral serving openings of suchshape that the entire surface of the bath'can be inspected and manipulated through. the" serving openingsn 3 One embodlment of the invention is, byi

Figure' l is a vertical section through an induction furnace, and Fig. 2- is asection on "2,;Fig. 1 looking from above.

duction furnace principally consists f' a l melting hearth .A," which; is provided, :with :a central opening a, and.. a n' endless; "iron-yoke B which has one 'leg- (B passing, 1

through the opening a "of 'the melting v Specification of I -etters Patent. Patented Dn. 14,1909; Application meam z' 1909f Serial No. 494,620.

hearth. A coil C. which con'ducts the pri-'- mary current from the machine is arranged T-ZT" melting hearth- A is provided a a melting trough or channel a which serves for holding the melting material 1) and.

which is completely covered bya vault. The

center-line of the trough extends in such' a manner that it forms a rhombi At the two corners of the .troughwhich form theacute angles of the rhomb are provided serving openings a which are'located abovethe surface of the melting loath and which can be closed by doors E. As shown in Fig.2 the two serving openings a of the improved (le vice are located in such a, manner relatively tothe melting trough that the-entire surface of the bath can be inspected and manipulated through the openings. It isv therefore possible, without the slightest difliculty 'to machines of the usualtype and to inspect the entire surface of the melting material and clean it to remove the slag; The. melt nace can be emptied by tilting.

Without departing from the spiritof the ing openings at two corners of the triangle charge the furnacesby means ofch'arg ng 1 invention the center-line of the melting the entire surface of the bath could also thenbeeinspectedl. H Having thus described the invention, .what

is claimed and desiredtobe secured by Let- 1. A melting 'he arthJfor electric induction:

furnaces having a' melting trough provided with lateral serving openings, said trough being ofa shape permitting inspection of and access to the entire surface of the bath inthe trough through said serving openings.

2 A melting hearth for electric induction furnaces having a'melting trough the center.

line of whichsforms-a rhomby and lateral ,1

serving openings l'ocated'atthe acute angles. 'of the'rhomb,

3 'A melting hearth for electric induction foregoing specification signedzitiBar I furnaces havin a melting trough of submen, (Jre rmany, this eighth (8th) a day of p stantiallyrhom Oidal shape. Ap1' il, l90'9. r ,1

4. A'melting hearth for electric induction H CARL 1 furnaces havin a melting trough of sub- Gtantiafiy rhom Qidal shape and a lateral In prsiehpe.of-

serving opening at eada of the cornea-e: 1m O'rm Kfmm; mg the acute angles of the rhomb. I C. J. VVRIGHT. I V 

